diff --git a/golang/client.go b/golang/client.go
index 0a7defaaa..5b59376ca 100644
--- a/golang/client.go
+++ b/golang/client.go
@@ -504,6 +504,7 @@ func (cli *defaultClient) startUp() error {
 			if err != nil {
 				cli.log.Errorf("scheduled queryRoute err=%v", err)
 			}
+			clearOldRouteSizeCache(oldRoute.([]*v2.MessageQueue))
 			if newRoute == nil && oldRoute != nil {
 				cli.log.Info("newRoute is nil, but oldRoute is not. do not update")
 				return true
@@ -529,6 +530,12 @@ func (cli *defaultClient) startUp() error {
 	ticker.Tick(f, time.Second*30, cli.done)
 	return nil
 }
+
+func clearOldRouteSizeCache(oldRoutes []*v2.MessageQueue) {
+	for _, route := range oldRoutes {
+		route.ClearSizeCache()
+	}
+}
 func (cli *defaultClient) notifyClientTermination() {
 	cli.log.Info("start notifyClientTermination")
 	ctx := cli.Sign(context.Background())
diff --git a/golang/protocol/v2/definition.pb.go b/golang/protocol/v2/definition.pb.go
index 63cdbe3f6..3c434592b 100644
--- a/golang/protocol/v2/definition.pb.go
+++ b/golang/protocol/v2/definition.pb.go
@@ -1389,6 +1389,13 @@ type MessageQueue struct {
 	AcceptMessageTypes []MessageType `protobuf:"varint,5,rep,packed,name=accept_message_types,json=acceptMessageTypes,proto3,enum=apache.rocketmq.v2.MessageType" json:"accept_message_types,omitempty"`
 }
 
+func (x *MessageQueue) ClearSizeCache() {
+	x.sizeCache = 0
+	x.Topic.sizeCache = 0
+	x.Broker.sizeCache = 0
+	x.Broker.Endpoints.sizeCache = 0
+}
+
 func (x *MessageQueue) Reset() {
 	*x = MessageQueue{}
 	if protoimpl.UnsafeEnabled {